HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Prochazka, A Articles by Ziccone, S P Search for Related Content PubMed PubMed Citation Articles by Prochazka, A Articles by Ziccone, S P

1. Electrical activity and length of ankle muscles were recorded by telemetry during free fall and landing in cats. 2. After foot contact, there was a delay in onset of stretch of ankle extensors of between 8 and 11 ms. High-speed cinematography showed the delay to be associated with rapid initial dorsiflexion of the toes. 3. Electromyograms (e.m.g.) from lateral gastrocnemius increased in amplitude prior to landing. An early depression of lateral gastrocnemius e.m.g. commenced at 8 ms after foot contact, and was followed by a large peak of activity commencing some 8 ms after the first increase in lateral gastrocnemius length. 4. Local anaesthesia of the plantar cushion did not alter this pattern of response. 5. The early inhibition of lateral gastrocnemius was attributed to the action on lateral gastrocnemius motoneurones of non-cutaneous afferents responding to the initial toe dorsiflexion. Additional autogenetic inhibition may also have contributed. 6. The subsequent peak of e.m.g. was at a latenty consistent with a rapid stretch reflex, and occurred soon enough for the resulting active tension to contribute significantly to the extensor force during body deceleration.

This article has been cited by other articles:

				J. Duysens, F. Clarac, and H. Cruse Load-Regulating Mechanisms in Gait and Posture: Comparative Aspects Physiol Rev, January 1, 2000; 80(1): 83 - 133. [Abstract] [Full Text] [PDF]